1. Field of the Invention
The present invention relates to dispensers for solid pasty materials such as cosmetic pomades and more particularly to carriers designed to facilitate insertion and retention of a solid pomade within the dispenser.
2. Description of the Related Art
Cosmetic products such as lipsticks, concealer sticks and lip balms, are typically marketed in dispensers that contain the cosmetic as a pomade or bullet mounted in a cup that is moved up and down along a track within a cylindrical sleeve to extend and retract the cosmetic for use. The pomade is loaded into the cup either automatically or manually. Typically, with manual filling, stick-shaped pomades are pre-formed in a mold, chilled and pressed into the cup holder of the dispenser by hand. With a popular-type of automatic filling, the pomades are molded upside-down in a continuous process, chilled, and then ejected out of the mold into the cup of the lipstick dispenser. For automatic filling, the pomade is formed into a bullet or cylindrical shape having a constant diameter throughout the length. Frictional forces between the pomade and the inside wall of the cup holder work to retain the pomade in the dispenser.
A recent trend in the cosmetic industry is the development of wear-resistant, silicone-based lipsticks. The volume of actual product of such lipsticks and the diameter of the pomade are considerably reduced compared to conventional lipsticks. The smaller diameter of the pomade and the tendency of silicone formulations to be slippery and to shrink over time pose a unique problem in maintaining the pomade in a conventional lipstick dispenser that relies on the contact of the pomade against the inside surface of the holding cup. Furthermore, silicone-type lipsticks when pressed or inserted in the cup tend to become crushed at the base which further weakens the attachment of the pomade base in the cup. To reduce such damage to the base, the pomade can be molded to have a diameter that steps down toward the base so that the base conforms with the diameter and shape of the cup. However, the disadvantage of a silicone-type lipstick with a stepped down base is that it is difficult to mold using current automatic processes in which the bullets are formed with straight sides to allow for ready demolding.
Attempts have been made to improve retention of cosmetic masses such as lipsticks in retractable dispensers. For example, U.S. Pat. No. 4,208,144 (Idec) and U.S. Pat. No. 4,983,059 (Holloway) disclose a dispenser made with a plurality of longitudinal rib-like structures on the inside surface of an elevator cup to assist in gripping the pomade and preventing it from shifting or becoming dislodged from the cup holder during use. U.S. Pat. No. 4,820,070 (Spatz) discloses ribs that are dovetail in cross-section and bite into the inserted cosmetic stick to prevent the stick from pulling away from the side wall of the pomade cup. However, none of these rib structures adequately and effectively retain a pomade in a cosmetic dispenser during use, particularly a silicone-based pomade.